While we mostly stay comfortable in our own little worlds, it is not impossible that an Old Timer or two might want to give this a go. I'd love to see a Dallaire or a Goldberg Sailplane once in a while.
As to alternative limits for FLIGHT TASKS, at one level, it doesn't really matter all that much -- at least relative to the kinds of flight tasks we have right now. On the other hand, an F5B plane will far, far exceed 200 meters in 15 seconds. Given the nature of the likely FLIGHT TASKS (not competition tasks), altitude switches are very inexpensive and very reliable. If a guy wants to meet competition requirements with an F5B comp let him have at it. If he wants to use an F3B plane to knock off a Flight Task, let him put a switch in it.
Happy Landings,
Don